FIG. 1 depicts a portion of a conventional energy assisted magnetic recording (EAMR) transducer 10 as well as recording media 16. For clarity, FIG. 1 is not to scale. The conventional EAMR transducer 10 is used in writing to the recording media 16. The EAMR transducer 10 receives light, or energy, from a conventional laser (not shown in FIG. 1). The conventional EAMR transducer 10 includes a conventional waveguide 20, which directs the light toward the media 16. The conventional waveguide typically includes a core 24 and cladding 22 and 26. Also shown are a conventional shield 12, a conventional pole 14, and a conventional near-field transducer (NFT) 30. Light from a laser (not shown) is incident on the grating (not shown), which couples light to the waveguide 20. Light is guided by the conventional waveguide 20 to the NFT 30 near the air-bearing surface (ABS). The light interacts with the NFT 30, which absorbs part of the optical energy and forms very strong localized electromagnetic field. When the localized electromagnetic field is close enough to the recording media 16, the recording media also absorbs part of the localized electromagnetic field and is heated. The pole 14 is then used to write to the heated region.
Although the conventional EAMR transducer 10 may function, it may be inefficient. The media recording efficiency is the ratio of the energy being absorbed by the magnetic recording medium to the incident optical energy. In the conventional EAMR transducer, the media absorption efficiency is on the order of a few percent at most. This low efficiency may be due to a number of factors. For example, there may be losses when light is coupled from the laser to the conventional waveguide 20, losses during propagation through the waveguide 20, a relatively weak interaction between the conventional waveguide 20 and the NFT 30, and the evanescent nature of localized electromagnetic field generated by the NFT 30. Efficiency of the EAMR transducer 10 is adversely affected.
Accordingly, what is needed is a system and method for improving efficiency and performance of the EAMR transducer.